In a typical HIC (Hybrid In-Cell) touch display screen, a touch sensing electrode (RX) is usually provided at one side of a CF (Color Filter) away from a liquid crystal layer while a common electrode (Common) at inner side of a TFT array substrate is partitioned into several pieces serving as touch driving electrodes (TXs). For avoiding mutual interference between display driving and touch driving, each TX signal output is at level of VCOM during time of displaying, and, during time of touch scanning, N pulse signals are output by every group of TX electrode and a TX signal is output once every N rows, where N depends on the number of gate lines and that of TX electrodes.
FIG. 1 is a block diagram illustrating a conventional touch driving circuit. As shown in FIG. 1, the driving circuit includes a scanning module 1 and a touch selective output module 2. Herein, the scanning module 1 provides the touch selective output module 2 with a strobe signal such that the touch selective output module 2 can generate a touch driving signal accordingly. As can be seen from FIG. 1, the conventional touch driving circuit is relatively complicated. When the conventional touch driving circuit is applied in a touch display electronic device, it will occupy a relatively large space at bezel area. Therefore, it is very difficult to implement the touch display device with a slim bezel, and the problem gets more serious especially for those handheld mobile devices (e.g., smart phones, tablet computers).
Moreover, as can be further seen from FIG. 1, there are relatively many signal input terminals (SDST, SDCK1, SDCK2, RESET, TXH and THL as shown in FIG. 1) in the driving circuit and thus there are relatively many controlling signals output by an IC (integrated circuit) for controlling them. This may raise the cost on the IC.